tree with data query generation

 public class Tree:Entity
    {
        public string id { get; set; }

        public string text { get; set; }

        public bool leaf { get; set; }

        public bool expanded { get; set; }
        public string path { get; set; }
        public List<Tree> children { get; set; }
    }

public Tree GetDeptListTree(string orgname)
        {
            Tree data = new Tree();
            List<Department> list = IDepartmentDao.GetDeptList();
            if (!string.IsNullOrEmpty(orgname))
            {
                List<Department> OrgList = new List<Department>();
                string[] ids = list.Where(x => x.ORG_NAME.Contains(orgname)).Select(a => a.ORG_PATH.Trim()).Distinct().ToArray();
                string orgids = string.Join(".", ids);
                List<Department> filteredlist = list.Where(x => orgids.Contains(x.ORG_ID.ToString()) || x.ORG_NAME.Contains(orgname)).ToList<Department>();
                OrgList = OrgList.Union(filteredlist).ToList();
                string[] OrgPaths = list.Where(x => x.ORG_NAME.Contains(orgname)).Select(a => (a.ORG_PATH.Trim() + "." + a.ORG_ID)).Distinct().ToArray();
                foreach (var OrgPath in OrgPaths)
                {
                    List<Department> LeafOrglist = list.Where(x => x.ORG_PATH.Contains(OrgPath)).ToList<Department>();
                    OrgList = OrgList.Union(LeafOrglist).ToList();
                }
                GetTreeChild(OrgList, "0", data, true, true);
            }
            else
            {
                GetTreeChild(list, "0", data, true, false);
            }
            return data;
        }

/// <summary>
        /// 生成树json数据
        /// </summary>
        /// <param name="list">数据集</param>
        /// <param name="rootid">根id</param>
        /// <param name="tree">实力类</param>
        /// <param name="leaf">叶子标识</param>
        /// <param name="expanded">是否展开</param>
        private void GetTreeChild(List<Department> list, string rootid, Tree tree, bool leaf, bool expanded)
        {
            tree.children = new List<Tree>();
            if (list.Count == 0)
                return;
            List<Tree> treelist = new List<Tree>();
            foreach (var item in list)
            {
                Tree treechild = new Tree();
                if (item.ORG_PARENT_ID.ToString() == rootid)
                {
                    treechild.id = item.ORG_CODE.ToString();
                    treechild.text = item.ORG_NAME.ToString();
                    treechild.path = item.ORG_PATH.ToString();
                    treechild.leaf = true;
                    treechild.expanded = item.ORG_PARENT_ID == 0 ? true : expanded;
                    tree.children.Add(treechild);
                    GetTreeChild(list, item.ORG_ID.ToString(), tree.children[tree.children.Count - 1], tree.leaf = false, expanded);
                }

            }
        }